The evaluation of post-operative alignment in total knee replacement using a CT-based navigation system

Area of Science:

• Orthopedic Surgery
• Medical Imaging
• Biomedical Engineering

Background:

• Accurate component alignment is crucial for the long-term success of total knee replacement (TKR).
• Conventional alignment guides may have limitations in achieving optimal component positioning.
• Navigation systems offer potential for enhanced precision in orthopedic procedures.

Purpose of the Study:

• To compare the accuracy of component alignment in total knee replacement surgery using a conventional alignment guide versus a CT-based navigation system.
• To evaluate the impact of a CT-based navigation system on coronal, sagittal, and rotational alignment of femoral and tibial components.

Main Methods:

• A comparative study involving 39 total knee replacements using conventional guides and 37 using a CT-based navigation system.
• All surgeries were performed by a single surgeon.
• Knee alignment was assessed using full-length weight-bearing anteroposterior radiographs, lateral radiographs, and CT scans.

Main Results:

• The CT-based navigation group achieved ideal alignment angles at significantly higher rates than the conventional group.
• Improvements were particularly noted in rotational alignment of both femoral and tibial components.
• Specific angular measurements for hip-knee-ankle, coronal femoral/tibial, sagittal femoral, and rotational femoral/tibial components were detailed for both groups.

Conclusions:

• CT-based navigation systems demonstrate significant improvements in component positioning during total knee replacement.
• Rotational alignment, a critical factor for TKR success, is especially enhanced by CT-based navigation.
• This technology offers a valuable tool for achieving greater accuracy in total knee arthroplasty.